Any ideas? I found a couple of these on my live rock tonight, in light of my leathers problems, I am considering them predatory and bad, until they are proven otherwise...They are living with the mantis shrimp at this point.

Aside from what Guy posted here and what Teri posted on RAG, I have found out that my mantis won't eat them....yet. I have only found the two, after removing them, I will wait and keep looking for more. If I find more and nothing appears to be disturbed or eaten by them, I'll probably leave them be. My biggest concern is that they could become a pest from simple numbers alon. The first one had already dropped a leg, when I looked in the mantis tank a couple of days later, one of them had dropped three legs after being moved....